function setText(startTag,endTag)
{
	var tagType = "html";
 	var field  = document.getElementById("contenu"); 
    var scroll = field.scrollTop;
    field.focus();
        
        /* === Partie 1 : on récupère la sélection === */
        if (window.ActiveXObject) {
                var textRange = document.selection.createRange();            
                var currentSelection = textRange.text;
        } else {
                var startSelection   = field.value.substring(0, field.selectionStart);
                var currentSelection = field.value.substring(field.selectionStart, field.selectionEnd);
                var endSelection     = field.value.substring(field.selectionEnd);               
        }
        
        /* === Partie 2 : on analyse le tagType === */
        if (tagType) 
		{
                switch (tagType) 
				{
					case "lien":
						endTag = "</lien>";
						if (currentSelection) 
						{ // Il y a une sélection
							if (currentSelection.indexOf("http://") == 0 || currentSelection.indexOf("https://") == 0 || currentSelection.indexOf("ftp://") == 0 || currentSelection.indexOf("www.") == 0) 
							{
								// La sélection semble être un lien. On demande alors le libellé
								var label = prompt("Quel est le libellé du lien ?") ;
							}
						}
					break;
                }
        }
        
        /* === Partie 3 : on insère le tout === */
        if (window.ActiveXObject) {
                textRange.text = startTag + currentSelection + endTag;
                textRange.moveStart("character", -endTag.length - currentSelection.length);
                textRange.moveEnd("character", -endTag.length);
                textRange.select();     
        } else {
                field.value = startSelection + startTag + currentSelection + endTag + endSelection;
                field.focus();
                field.setSelectionRange(startSelection.length + startTag.length, startSelection.length + startTag.length + currentSelection.length);
        } 

        field.scrollTop = scroll;     
}